We will study the influence of four dietary factors, namely cholesterol, ethanol, lecithin, and unsaturated versus saturated fat, on plasma lipoprotein, and lipid distribution and concentration. To determine dietary effects on lipoprotein structure, measurements of physical properties and chemical composition will be carried out. Experiments have been planned in factorial design so that the counterbalancing or synergistic interactions among the dietary ingredients that affect lipoprotein structure and concentration will be learned. Dietary ingredients to be studied were selected to maximize variability in HDL response. African green monkeys will be used as animal models because of their known similarities to human beings in lipoprotein response to diet, and to permit metabolic studies of HDL formation and catabolism. Thoracic lymph duct cannulated animals will be used to study dietary effects on several aspects of HDL formation in the intestine. These studies were designed to test the hypothesis that dietary factors influence the rate and amount of production, the chemical composition, and the physical properties of the precursor lipoproteins of the intestine, (primarily the chylomicra) which are then reflected in the properties, turnover rates, and eventual concentrations of HDL. At the completion of the study, some of the animals will be killed and the extent and severity of coronary artery atherosclerosis will be measured. Relationships between diet, lipoproteins, and atherosclerosis among the same individuals can then be used to establish the atherogenic features of diet-induced hyperlipoproteinemia.